Namco Museum Classics Volume 4 Codes -

Return Of Ishtar game:
Enter the Museum and go to the Return Of Ishtar room. Quickly press Right, Left, Up, Down, Circle. A hidden version of the Return of Ishtar game will begin.

The Genji and the Heike Clans: Escape From "Hell" Stage:
During the game, when you fall off a cliff, you will be transported to "Hell". While in Hell, do not kill the spider webs just yet - keep killing the green spiders and collecting the gems they leave behind. When you have collected 80 or more gems, go to the red "acid pit" and go straight to the center. You will have "bought" your way out of Hell. The old person will appear and say, "Even hell depends on money." You will reappear in the "Kyoto" stage, and the game will continue as normal.

Alternate introduction:
Hold L1 + R1 when the Namco logo scrolls past while the game is loading. The FMV introduction sequence from the Genji and Heiki Clan will be displayed.

Extra credits:
Press Select to increase the number of credits available in any game as many times as needed.